A 


Field  Museum  of  Natural  History. 

Publication  187. 

Botanical  Series.  •  Vol.  II,  No.  11. 


I.  CONTRIBUTIONS  TO  NORTH  AMERICAN 
EUPHORBIACEAE— VI 

II.  VEGETATION  OF  ALACRAN  REEF 


BY 

Charles  Frederick  Millspaugh 
Curator  Department  of  Botany. 


Chicago,  U.  S.  A. 

April,  1916. 


Field  Museum  of  Natural  History. 

Publication  187. 

Botanical  Series.  Vol.  II,  No.  11, 


I.  CONTRIBUTIONS  TO  NORTH  AMERICAN 
EUPHORBIACEAE— VI 

II.  VEGETATION  OF  ALACRAN  REEF 


BY 

Charles  Frederick  Millspaugh 
Curator  Department  of  Botany. 


Chicago,  U.  S.  A. 

April,  19 1 6. 

Issued  Apr. 28, 1916. 


contributions  to  north  american 
euphorbiace;e-vi 


CHARLES  F.  MILLSPAUGH,  M.  D. 

Chamaesyce  S,  F.  Gray,  Nat.  Arr.  Brit.  PL  2:260.     1821. 

Leaves  opposite,  inaeqtiilateral;  inflorescence  solitary  or  capitulate, 
axillary  and  terminal;  bracteoles  plumose  or  ciliate;  seeds  minute, 
ovoid  or  elongate-ovoid,  more  or  less  quadrangular  the  facets  smooth  or 
transverse-rugulose . 

Type  species:  Euphorbia  peplis  Linn.  Sp.  PI.  652.     1753. 

Chamaesyce  barbicarina  sp.  nov. 

Plants  semi-erect,  about  2dm.  high,  annual.  Stems  many,  from  a 
but  slightly  raised  rootstalk ;  branches  many,  virgate,  terete,  long-pilose 
especially  upon  the  upper  surface.  Inflorescence  solitary  in  the  axils 
of  the  terminal  branchlet  leaves.  Leaves  opposite,  5-8  x  2-4mm., 
ovate,  obtuse,  broadest  at  the  roimded  apex,  base  strongly  auriculo- 
oblique,  glabrous  the  thickened  margin  crenate-dentate;  petioles  about 
I  mm.,  hairy;  stipules  broadly  triangular-lanceolate,  lacerate.  In- 
volucres turbinate,  glabrous  without  and  within;  peduncle  about  the 
length  of  the  involucre  (in  fruit  twice  the  length);  involucral  lobes 
triangular,  ciliate;  siilcus  shallow;  glands  scutelliform;  appendages  white, 
irregular-ovate,  margin  crenate  or  2-3-crenate-dentate;  bracteoles  none; 
male  pedicels  few,  short;  female  pedicel  ciHate-hairy;  styles  short, 
bilobed  at  the  apex.  Capsule  obpyriform,  glabrous  except  on  the  blunt 
keels  of  the  otherwise  smooth  carpels  which  are  long-ciliate  fringed; 
seeds  red,  ovoid,  acute,  .9  x  .6mm.,  angles  sharp,  facets  marked  by  a  few 
very  slightly  raised  irregtilar  and  broken  transverse  ridges. 

Between  Ch.  dioica  and  Ch.  yucatanensis  but  readily  distinguished 
from  both  by  the  peculiar  ciliate-fringed  keels  of  the  carpels. 

Sitilpech  Road,  November,  1895,  Gaumer  939a  (Type  sheet, 
Field  Mus.  cat.  no.  196,352.)  It  was  gathered  as  a  part  of  a  mass  of  Ch. 
rutilis  by  the  collector.  Also  collected  at  Chichankanab,  Gaumer  1432, 
2074;  and  at  Pocoboch  2405. 

401 


402    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

Chamaesyce  cozumelensis  comb.  nov. 

Etiphorbia  cozumelensis  Millsp.  Field.  Mus.  Bot.  2:261.     1900. 

A  large  number  of  sheets  of  this  species  show  an  intergradation  from 
the  absolutely  glabrous  and  glaucous  original  collection,  on  Cozumel 
Island,  through  a  form  with  a  few  long,  scattered  hairs  in  the  capsular 
sulci  {E.  cozumelensis  pilosulca  Millsp.  ibid.  262) ;  a  form  with  a  few  long 
hairs  on  the  nodes,  petioles  and  leaves;  to  plants  densely  long-pilose 
throughout.  The  extremes  of  these  plants  appear  like  widely  different 
species  but  the  characters  do  not  warrant  the  application  of  even  varietal 
names. 

The  distribution  of  the  forms  is  as  follows:  The  glaucous  form  — 
Cozimiel  Island,  Millspaugh  1604, 1606, 1608,  i6og,  1611;  the  form  with 
the  capsular  siilci  hairy  —  Cozumel  Island,  Millspaugh  1501,  1502; 
the  form  with  the  nodes,  petioles  and  leaves  long-pilose  —  Cozimiel 
Island,  Millspaugh  4Q,  53,  Chichankanab,  Gaumer  1456;  whole  plant 
densely  long-pilose  —  Mugeres  Island,  Millspaugh  24,  Izamal,  Silam 
and  Progreso,  Gaumer  J14,  62Q,  1887,  2407. 

Chamaesyce  hirta  (L.)  Millsp.  Field  Mus.  Bot.  2:303. 

I  have  gathered  a  large  number  of  forms  of  this  species  from  many 
localities  in  Hawaii,  south  China,  Straits  Settlements,  Java,  the  PhiHp- 
pines,  Burma,  India,  and  from  Bermuda,  Florida  and  the  Bahamas 
through  the  West  Indian  islands,  Mexico  and  South  America  to  Pemam- 
buco,  Brazil.  With  all  this  material  and  a  large  number  of  sheets  from 
other  collectors  I  can  not  satisfy  myself  that  there  is  any  specific  dif- 
ferentiation between  E.  hirta  and  E.  pilulifera  L,,  capitata  Lam.,  globuli- 
fera  Kth.,  verticillata  Veil.,  nodiflora  Steud.,  procumbens  DC,  obliterata 
Jacq.,  ophthalmica  Pers.,  discolor  Engelm.,  gemella  Lag.,  and  Karwin- 
skyi  Boiss.  the  type  material  of  all  of  which  I  have  examined.  These 
are  only  intergradient  forms  and  there  are  a  multitude  of  others  that 
have  luckily  escaped  specific  nomination. 

Chamaesyce  Rosei  sp.  nov. 

Annual,  short-crispid-multicellular  hairy.  Root  straight  and  deep; 
stems  many,  terete,  wiry;  intemodes  long;  branches  profuse,  ascending. 
Inflorescence  in  terminal,  globose  heads.  Leaves  inaequilateral, 
narrowly  lanceolate,  13-25  x  3-6mm.,  crisp-hairy  on  both  surfaces  and 
with  a  broad,  deep-red,  central  line  of  maciilation;  apex  acute;  base 
narrowing  to  the  petiole;  margin  shallow-toothed  toward  the  apex; 
petioles  short  (about  2mm.);  stipules  mere  aristate  teeth  about  .8mm. 
long.  Involucres  turbinate,  roseate,  sessile  or  nearly  so,  thin  walled, 
the  outer  surface  pubescent  the  inner  densely  bearded;  lobes  deltoid. 


April,  1916.  Euphorbiace^e  —  Millspaugh  403 

aristate;  sulcus  V-shaped,  the  fundus  occupied  by  2-3-aristate  lobes; 
glands  minute,  stipitate,  cupulate;  appendages  roseate,  distant  from  the 
glands  and  but  Httle  larger,  inserted  about  half  way  down  the  stipe;  male 
flowers  about  6,  short,  absent  in  many  involucres  of  each  cluster; 
filaments  glabrous;  female  flower  short  pedicelled;  ovary  densely  pubes- 
cent ;  styles  roseate,  bifurcate  two-thirds  their  length,  the  branches  di- 
varicate and  somewhat  capitulate  at  the  stigmatic  tips.  Capsule 
strongly  tricoccous,  bearing  very  short,  thick,  crispid,  golden,  multicel- 
lular hairs;  seeds  pink-ashen,  ovate-quandrangular,  acute,  .8  x  .5mm., 
angles  sharp,  facets  marked  by  irregular,  complete  and  incomplete 
transverse  ridges. 

Near  Ch.  hirta  (L.)  Millsp. 

Mexico,  along  an  arroyo  in  the  vicinity  of  Alamos,  State  of  Sonora, 
Rose,  Standley  6°  Russell,  March  13,  1910,  12728  (Type  in  herb.  New 
York  Botanical  Garden). 

Chamaesyce  vallis-mortae  sp.  nov. 

Perennial  from  a  long,  cylindrical  root;  densely  woolly-pubescent 
above.  Stems  many,  \dry,  divergently  branching  toward  the  tips. 
Inflorescence  solitary  in  the  leaf  axils  of  the  branchlets.  Leaves  thick, 
ovate,  cordate,  roimded  at  the  apex,  entire,  5  x  4  —  6  x  5mm.,  densely 
woolly  on  both  surfaces;  petioles  about  imm.  long;  stipules  short, 
triangular,  cihate.  Involucres  campanulate;  peduncle  about  one-third 
the  length  of  the  tube;  outer  surface  woolly,  inner  surface  fasciculate- 
hairy;  lobes  triangular;  sulcus  deeply  V-shaped,  the  fundus  unoccupied; 
glands  green,  longitudinal,  scutelliform;  appendages  large,  white, 
flabelliform,  the  outer  margin  papulo-ciliate  and  often  slighty  3-crenate; 
male  flowers  about  6,  glabrous;  female  flower  pedicellate;  ovary  woolly- 
pubescent;  styles  bifid  two-thirds  their  length,  the  branches  divergent 
not  swollen  at  the  stigmatic  tips.  Capsule  obpyriform,  hairy;  seeds 
salmon-color,  quadrangular-ovate,  pointed,  the  angles  rounded,  facets 
smooth  or  nearly  so. 

Near  Ch.  tonsita  Millsp. 

California,  Death  Valley  between  Mohave  and  Keeler,  alt.  750 
meters,  June  21,  1891,  Coville  b'  Funston  1008  (Type  in  U.  S.  National 
Herbarium  cat.  no.  16203). 

Chamaesyce  tamaulipasana  sp.  nov. 

Annual,  prostrate,  pilose.  Stems  many  from  the  thickened  rootstalk ; 
branches  unilateral  on  the  stems,  densely  foHate;  branchlets  very  short. 
Inflorescence  solitary  in  the  axils  of  the  branchlet  leaves.  Leaves  ap- 
pressed,  inaequilateral,  ovate,  acute,  cordate,  entire,  3.5x2- 5x3 


404    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

mm.,  long-crisp-hairy  on  both  surfaces;  petioles  short,  thick;  stipules 
elongate-linear,  hairy.  Involucres  elongate-turbinate  narrowing  to 
the  peduncle  which  is  about  the  length  of  the  tube;  both  surfaces  pilose; 
sulcus  U-shaped  with  a  short,  linear  lobe  in  the  fundus;  glands  trans- 
verse, ovoid,  short  stipitate,  scutelliform;  appendages  fiabelliform, 
twice  the  width  of  the  glands,  entire,  the  margin  papilliform-ciliate; 
male  flowers  few;  pedicels  glabrous;  filaments  very  short;  female  flower 
pedicellate;  ovary  densely  pilose;  styles  bifurcate  to  the  middle,  the 
stigmatic  lobes  divergent.  Capsule  obpyriform,  pilose,  strongly  tri- 
coccous;  seeds  red-ashen,  elongated  ovoid-quadrangular,  pointed,  1.2  x 
.5mm.,  angles  sharp;  facets  nearly  smooth,  indistinctly  marked  by  a 
median  longitudinal  line  approached  on  both  sides  by  numerous,  ir- 
regular, faint,  transverse  ridges. 

Near  Ch.  velleriflora  (Boiss). 

Known  only  from  the  vicinity  of  Victoria,  Tamaulipas,  Mexico, 
where  it  was  collected  by  Dr.  Edward  Palmer,  Feb.  i— Apr.  9,  1907  as 
his  no.  98  (Type  in  herb.  Field  Museum  cat.  no.  217,435), 

Chamaesyce  Standleyi  sp.  nov. 

Annual,  prostrate,  finely  pilose.  Stems  many,  from  a  thickened  root- 
stalk;  branches  densely  pilose,  short,  each  subtended  by  a  pair  of  large 
leaves;  branchlets  very  short.  Inflorescence  solitary  in  the  axils  of  the 
branchlet  leaves.  Leaves  strongly  inaequilateral,  ovate,  3  x  4—5  x  10 
mm.,  nearly  glabrous,  cordate,  blunt,  lightly  crenate-dentate  more  pro- 
nounced at  the  rounded  apex;  petioles  short  (.8mm.);  stipules  linear 
entire.  Involucres  cylindro-turbinate  on  a  very  short  peduncle  with 
bract-like  leaflets  at  the  base,  densely  pilose  without  and  within; 
lobes  triangular,  long-ciliate;  sulcus  narrow,  about  half  the  depth  of  the 
involucral  tube,  fundus  unoccupied;  glands  transverse,  narrowly  scutelli- 
form and  somewhat  plicate;  appendages  white,  rounded,  entire,  very 
narrow  on  the  lower  and  somewhat  broader  on  the  upper  pair  of  glands; 
male  flowers  few,  very  short  pedicelled  and  inserted  in  a  ring  at  the 
base  of  the  tube,  not  as  long  as  the  pedicel  of  the  female  flower;  glabrous; 
female  flower  short  pedicelled;  ovary  obpyriform,  pilose;  styles  long, 
bifurcate  at  the  apex.  Capsule  pilose,  deeply  tricoccous;  seeds  ashen, 
ovoid-quadrangular,  blunt,  .9  x.  4mm.,  the  angles  sharp  and  somewhat 
included  by  the  ridges;  facets  marked  by  3-4  often  incomplete  transverse 
ridges. 

Near  Ch.  thymifoHa  (Burm.). 

Only  known  from  the  vicinity  of  Acaponeta,  Tepic,  Mexico,  where  it 
was  collected  by  Rose,  Standley  b'  Rose,  Apr.  10, 1910,  no.  14342  (Type  in 
U.  S.  National  Herbarium  cat.  no.  637,211). 


April,  1916.  Euphorbiace^  —  Millspaugh  405 

Chamaesyce  sulfurea  sp.  no  v. 

Annual,  prostrate-rosulate,  siilphur  color  when  dried,  glabrous. 
Root  short;  stems  many,  radiating  from  the  rootstalk,  thick,  terete; 
branches  and  branchlets  many,  dichotomous.  Inflorescence  solitary  in 
the  leaf  axils  throughout  the  plant.  Leaves  ovate-lanceolate,  inaequi- 
lateral,  somewhat  falcate,  5x3-11x7  mm.,  the  midrib  prominent 
beneath,  base  unequally-cordate,  apex  acute,  margin  entire,  somewhat 
thickened  and  revolute;  petioles  about  one-quarter  the  length  of  the 
blade;  stipules  lacerate-fimbriate.  Involucres  globular,  5 -columnar, 
glabrous;  peduncle  two-thirds  the  length  of  the  tube;  involucral  lobes 
deltoid,  truncate,  3-toothed  at  the  apex;  sulcus  shallow,  rounded,  unoc- 
cupied; glands  large,  stipitate,  scutelliform;  appendages  none;  bracteoles 
numerous,  ligulate,  interspersed  with  5,  thin,  lanceolate,  fimbriate, 
ciliate  petaloid  rudiments;  stamens  few,  filaments  short,  glabrous; 
female  flower  long-coliminar-pedicellate,  glabrous;  ovary  smooth,  styles 
clustered  in  an  erect  close  mass  nearly  as  large  as  the  ovary  itself, 
styles  thick,  clavellate,  approximate,  bifurcate  to  the  middle.  Capstile 
strongly  tricoccous,  the  carpels  smooth,  line  of  dehiscence  strongly 
marked;  seeds  white,  1.5  x  i  mm.,  dorsal  angle  prominent,  the  whole 
surface  beautifully  sculptured  into  short,  rounded,  high,  broken  trans- 
verse ridges  appearing  like  a  miniature  white  cluster  of  earthworm  casts. 

Near  Ch.  ocellata  from  which  the  seeds  readily  differentiate  it. 

Type  station  Butte  Co.,  California,  on  hills  east  of  Chico,  near  Big 
Chico  Creek,  September  16,  1913,  A.  A.  Heller  11 140  (Type  in  herb. 
Field  Museum  cat.  no.  411,411).  Also  collected  at  or  near  the  type 
station  by  H.  M.  Hall,  July,  1914,  9759- 

Chamaesyce  Gooddingii  sp.  nov. 

Glabrous,  prostrate,  annual,  reddish-green  in  general  color,  with  a 
mass  of  wiry  stems  and  branches  from  the  somewhat  thickened  root- 
stalk.  Inflorescence  solitary  in  the  terminal  axils.  Leaves  ovate, 
obtuse,  4  X  2-7  X  5  mm.  palmately  3-nerved,  the  midvein  prominent 
beneath,  unequally  cordate,  margin  entire;  petioles  about  one-quarter 
the  length  of  the  blade;  stipules:  the  lower  filiform,  entire,  the  upper 
ligulate  and  often  few-lacerate  at  the  apex.  Involucres  turbinate, 
glabrous,  peduncles  about  one-half  the  length  of  the  tube;  lobes  triangu- 
lar, apiciilate,  the  margins  blunt-ciliate;  sulcus  shallow,  its  fundus  oc- 
cupied by  a  narrow,  lanceolate  fiifth  lobe;  glands  stipitate,  transversely 
narrow-scutelliform,  the  outer  edge  crenate-dentate  to  the  appearance  of 
an  appendage;  bracteoles  none;  petaloid  rudiments  flabelliform,  many- 
fimbriate;  stamens  few,  filaments  long,  glabrous;  female  flowers  long- 
pedicelled,  glabrous,  styles  divergent,  bilobate  at  the  apex.     Capsule 


4o6    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

glabrous,  strongly  tricoccous,  the  carpels  rounded-keeled  and  minutely 
white-punctate;  seeds  white,  .gx  .5  mm.,  elongated  ovoid-quandrangular, 
angles  rounded,  the  dorsal  prominent;  facets  marked  medially  with  two 
longitudinal  lines  of  short,  rounded,  inconspicuous,  irregular,  transverse 
rugae. 

Near  Ch.  sulfurea  from  which  its  seed  readily  differentiate  it. 

Type  locality  Lee  Canyon,  Charleston  Moimtains,  in  limestone  at 
8000  ft.  alt.,  Clark  Co.,  Nevada,  A.  A.  Heller  11058  (Type  in  herb. 
Field  Musetmi  cat.  no.  411,087);  previously  gathered  by  Leslie  N. 
Goodding,  in  sandy  washes  at  Las  Vegas,  Nevada,  in  1907,  No.  2282. 

Chamaesyce  aureola  sp.  no  v. 

An  erect,  or  prostrate,  pilose  annual  (?)  with  a  ligneous  root  from 
which  spreads  a  dense  mass  of  terete,  divaricate  branches  and  branchlets. 
Inflorescence  solitary,  terminal  and  upperaxillary.  Leaves  thick, 
strongly  inaequilateral,  ovate,  obtuse,  2-4  x  1.5-2  mm.,  densely  pilose, 
cordate,  entire;  petioles  less  than  one-half  the  length  of  the  blade; 
stipules:  the  lower  deltoid,  the  upper  filiform,  those  of  the  upper  surface 
with  a  flat,  purplish  gland  at  the  base.  Involucres  turbinate,  the  throat 
densely  pilose;  peduncle  about  one-half  the  length  of  the  tube;  tube 
densely  pilose  without  and  within;  lobes  deltoid,  pilose;  sulcus  V-shaped; 
glands  transverse,  oblong,  reddish-brown,  fiat  and  but  little  cupped; 
appendages  large,  white  or  creamy,  ovate,  nearly  entire;  bracteoles 
many,  ligulate,  glabrous;  stamens  few,  filaments  glabrous,  the  joint 
close  to  the  anther  base;  female  pedicel  thick,  pilose;  ovary  pilose; 
styles  3,  bifurcate  to  the  middle,  the  branches  divaricate  and  not  sensibly 
enlarged  at  their  stigmatic  apices.  Capsule  strongly  tricoccous,  densely 
pilose;  seeds  smooth,  white,  creamy- white  or  sage-color,  elongate-ovate, 
1.2  X  .6  mm.,  the  dorsal  angle  prominent,  4-angled  at  the  base,  pointed 
at  the  apex,  the  facets  smooth  and  showing  but  a  few  slight  indications  of 
scattered  pits. 

Near  Ch.  polycarpa  and  Ch.  vestita  from  each  of  which  the  characters 
readily  distinguish  it. 

So  far  seen  only  in  a  series  of  specimens  collected  at  Azusa,  Los 
Angeles  Co.,  California,  at  an  elevation  of  800  ft.  Huron  H.  Smith  4933 
(Type  in  herb.  Field  Museimi  cat.  no.  389,282). 

Chamaesyce  prostrata  (Ait.)  Small  Fl.  SE.  U.  S.  713,  1333.     1903. 

A  species  of  wide  distribution  misinterpreted  in  previous  Yucatan 
publications  of  species  as  E.  rhytisperma  and  serpyllifolia  on  account  of 
variation  from  the  type  form. 

The  species  is  represented  in  the  Yucatan  Flora  by  Schoti  g6ya  from 
Merida  where  it  was  gathered  in  a  mass  of  Ch.  hirta;  Millspaugh  27 


April,  1916.  Euphorbiace^  —  Millspaugh  407 

(1887),  also  from  Merida;  Gaumer  254  from  cultivated  ground  at  Izamal, 
460  from  stone  walls  at  the  same  place,  and  on  waste  ground  at  Tekax, 
1123, 

Chamaesyce  rutilis  Millsp.  Field  Mus.  Bot.  2:385.     1914- 

This  species  of  Guatemala  and  Honduras  has  turned  up  in  the 

Yucatan  region.     The  type  is  Chas.  C.  Deam,  6i8g,  Field  Mus.  cat.  no. 

285,111  from  Fiscal,  Guatemala,  alt.  3700  ft. 

The   Yucatan   localities   are:  Chaltumha   Road,    Sitilpech   Road, 

Gaumer  pjS,  gjg. 

Chamaesyce  vilHfera  (Scheele)  Small  Fl.  SE.  U.  S.  712,  1333.     1903. 

The  previously  known  range  of  this  striking  species,  Texas  to  Orizaba, 
Mexico,  is  extended  farther  south  by  a  number  of  specimens  collected 
by  Dr.  Gaumer  at  Buena  Vista  Xbac  and  Chichankanab,  Yucatan,  1103, 
1 186,  222g. 

Chamaesyce  jmcatanensis  sp.  nov. 

Rosulate-prostrate  from  a  slender  annual  root;  stem  and  branches 
filiform,  pilose.  Inflorescence  solitary  in  the  axils  of  the  upper  leaves. 
Leaves  inaequilateral,  5-7  x  2-4  mm.,  oblong-lanceolate,  strongly  obli- 
que at  the  base,  acute,  the  margin  distantly  serrate;  petioles  about  imm. 
long;  stipules  represented  below  by  a  somewhat  denser  mass  of  the  stem 
hairs,  above  by  a  scale-like,  waxy  gland  at  the  base  of  the  petiole.  In- 
volucres tubular-campanidate,  sessile  or  apparently  so,  pilose  without 
glabrous  within;  lobes  represented  by  clusters  of  hairs  except  where 
flanking  the  deep,  round-based  sulcus  where  they  are  triangular,  acute; 
glands  bright-green,  scutelliform,  appendages  white,  unequal,  about 
twice  the  size  of  the  glands,  ovate,  unequally  crenate-margined;  brac- 
teoles  none;  male  pedicels  3-5;  female  pedicel  about  the  length  of  the 
ovary;  styles  3,  bifurcate  at  the  upper  third;  ovary  pilose.  Capsule 
pilose,  ovoid,  deeply  sulcate;  seed  pinkish-ashen,  .8x  .5  mm.,  sharply 
angled,  the  facets  marked  by  irregular  and  broken  transverse  ridges. 

Near  Ch.  cozumelensis. 

Progreso,  Yucatan,  on  the  rocky  plain  south  of  the  lagoon,  Mills- 
paugh i6g6,  March  5,  1899.  Type  in  herb  Field  Mus.  cat.  no.  61,696. 
Erroneously  referred  to  Ch.  Karwinskyi  (Boiss.)  {E.  Karwinskyi  Boiss.) 
in  Field  Mus.  Bot.  2 :65. 

The  other  North  American  species  of  this  genus  not  previously  trans- 
ferred to  it  are : 

Chamaesyce  acuta  (Engelm) 

Euphorbia  acuta  Engelm.  Mex.  Bound.  189. 


4o8    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

Chamaesyce  albescens  (Urban) 

Euphorbia  portoricensis  albescens  Urban  Symb.  Antill.  i  '.Z2>9- 
Chamaesyce  ammatotricha  (Boiss.) 

Euphorbia  ammatotricha  Boiss.  Cent.  Euph.  lo. 
Chamaesyce  Andromedae  (Millsp.) 

Euphorbia  Andromedae  Millsp.  Field  Mus.  Bot.  2:63. 

Chamaesyce  anychioides  (Boiss.) 

Euphorbia  anychioides  Boiss.  Cent.  Euph.  12. 
Chamaesyce  arenicola  (Parish) 

Euphorbia  arenicola  Parish  Erythea  7:93. 

Euphorbia  cuspidata  Engelm,  in  herb,  non  Bertol. 
Chamaesyce  astyla  (Engelm.) 

Euphorbia  astyla  Engelm.  Boiss.  DC.  Prodr.  15:40. 
Chamaesyce  Balbisii  (Boiss.) 

Euphorbia  Balbisii  Boiss.  Cent.  Euph.  11. 
Chamaesyce  bartolomaei  (Greene) 

Euphorbia  bartolomaei  Greene  Pittonia  1:290. 
Chamaesyce  Brandegeei  (Millsp.) 

Euphorbia  Brandegeei  Millsp.  Proc.  Calif.  Acad.  ser.  2,  2:226. 
Chamaesyce  bryophylla  (Donn-Sm.) 

Euphorbia  bryophylla  Donnell-Smith  Bot.  Gaz.  56:62. 

Chamaesyce  capitellata  (Engelm.) 

Euphorbia  capitellata  Engelm.  Mex.  Bound.  2:188. 
Chamaesyce  carmenensis  (Rose) 

Euphorbia  carmenensis  Rose  Contr.  U.  S.  Nat.  Herb.  1:133. 
Chamaesyce  centmiculoides  (Kth.) 

Euphorbia  centunculoides  HBK.  Nov.  Gen.  2:41. 
Chamaesyce  chalicophila  (Wetherb.) 

Euphorbia  chalicophila  Wetherb.  Proc.  Am.  Acad.  45:426. 

Chamaesyce  chamaecaula  (Wetherb.) 

Euphorbia  chamaecaula  Wetherb.  idem. 
Chamaesyce  conjuncta  (Millsp.) 

Euphorbia  conjuncta  Millsp.  Proc.  Calif.  Acad.  ser.  2,  2:227. 
Chamaesyce  consanguinea  (Engelm.) 

Euphorbia  consanguinea  Engelm.  Mex.  Bound.  187. 
Chamaesyce  crassinodis  (Urban) 

Euphorbia  crassinodis  Urban  Symb.  Antill.  i  :34o. 
Chamaesyce  cumbrae  (Boiss.) 

Euphorbia  cumbrae  Boiss.  Cent.  Euph.  i6r. 


i 


April,  1916.  Euphorbiace/E  —  Millspaugh  409 

Chamaesyce  Deppeana  (Boiss.) 

Euphorbia  Deppeana  Boiss.  Cent.  Euph.  6. 
Euphorbia  Anthonyi  Brandegee  Erythea  7:7. 
Euphorbia  clarionensis  Brandegee  idem. 

Although  Deppe  remarks  "in  California"  he  must  have  collected  the 
plant  on  some  one  of  the  out  islands  near  the  California  coast.  The 
species  has  not  been  found  on  the  mainland. 

Chamaesyce  dorsiventralis  (Urban) 

Euphorbia  dorsiventralis  Urban  Symb.  Antill.  5:391. 

Chamaesyce  floribunda  (Engelm.) 

Euphorbia  floribunda  Engelm.  Boiss.  DC.  Prodr.  15:39. 

Chamaesyce  florida  (Engelm.) 

Euphorbia  florida  Engelm.  Mex.  Bound.  189. 

Chamaesyce  fruticosa  (Engelm.) 

Euphorbia  fruticosa  Engelm.  Boiss.  DC.  Prodr.  15:38, 

Chamaesyce  Garkeana  (Boiss.) 

Euphorbia  Garkeana  Boiss.  DC.  Prodr.  15:38. 

Chamaesyce  glyptosperma  (Engelm.)  Small  Fl.  SE.  U.  S.  712;  1333. 
Euphorbia  Greenei  Millsp.  Pittonia  2 :88, 
Chamaesyce  aequata  Lun.  Am.  Midi.  Nat.  1:204. 
Chamaesyce  aequata  claudicans  Lun.  ibid  205. 
Chamaesyce  glyptosperma  integrata  Lim.  ibid  3:142. 

Chamaesyce  gracillima  (Wats.) 

Euphorbia  gracillima  Wats.  Proc.  Am.  Acad.  21:438. 

Chamaesyce  grisea  (Engelm.) 

Euphorbia  grisea  Engelm..  Boiss.  DC.  Prodr.  15:41. 

Chamaesyce  gjrmnadenia  (Urban) 

Euphorbia  gymnadenia  Urban  Symb.  Antill.  5:390. 

Chamaesyce  Heraldiana  nom.  nov. 

Euphorbia  glaberrima  Klotz.  Seem.  Bot.  Herald.  276,  non  Koch. 

Chamaesyce  hirtula  (Engelm.) 

Euphorbia  hirtula  Engelm.  Wats.  Bot.  Calif.  2:74. 

Chamaesyce  incerta  (Brandegee) 

Euphorbia  incerta  Brandeg.  Proc.  Calif.  Acad.  ser.  2,  3:171. 

Chamaesyce  interaxillaris  (Fern.) 

Euphorbia  interaxillaris  Femald  Proc.  Am.  Acad.  36:495. 

Chamaesyce  intennixta  (Wats.) 

Euphorbia  intermixta  Watson  Proc.  Am.  Acad.  24:74. 


4IO    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

Chamaesyce  involuta  (Millsp.) 

Euphorbia  involuta  Millsp.  Proc.  Calif.  Acad,  ser,  2,  2:227  et  3:170. 
Chamaesyce  Jonesii  (Millsp.) 

Euphorbia  Jonesii  Millsp.  Pittonia  2 :89. 

Chamaesyce  leucantha  (Kl.  &  Gke.) 

Anisophyllum  leucanthiim  Id.  &  Gke.  Tricocc.  27. 

Chamaesyce  leucophylla  (Bth.) 

Euphorbia  leucophylla  Bentham  Bot.  Sulph.  50. 
Euphorbia  velutina  Greene  Biill.  Calif.  Acad,  ser,  2,  5:57. 

Chamaesyce  liliputiana  (Wright) 

Euphorbia  liliputiana  Wright  Urban  Symb.  Antill.  5:390. 
Euphorbia  minutula  Boiss.  DC.  Prodr.  15:1263. 

Chamaesyce  linearis  (Retz.) 

Euphorbia  linearis  Retz.  Obs.  3:32. 

Euphorbia  ariiculata  Aubl.  PL  Gui.  i  :48o. 
Chamaesyce  lineata  (Wats.) 

Euphorbia  lineata  Wats.  Proc.  Am.  Acad.  21:454. 
Chamaesyce  longeramosa  (Wats.) 

Euphorbia  longeramosa  Watson  Proc.  Am.  Acad.  25:161. 
Chamaesyce  luisensis  nom.  nov. 

Euphorbia  tomentella  Engelm.  Boiss.  DC.  Prodr.  15:32, 
non  Zipp.  ex  Span,  in  Linnaea  15:350. 
Chamaesyce  magdalenae  (Benth.) 

Euphorbia  magdalenae  Bentham  Bot.  Sulph.  50. 
Chamaesyce  melanadenia  (Torrey) 

Euphorbia  melanadenia  Torr.  Pacif.  R.  R.  Exped.  4-'i35- 

Euphorbia  polycarpa  vestita  Wats.  Bot.  Calif.  2:73. 
Chamaesyce  Mendezii  (Boiss.) 

Euphorbia  Mendezii  Boiss.  Cent.  Euph.  15. 
Chamiaesyce  multinodis  (Urban) 

Euphorbia  multinodis  Urban  S>Tmb.  Antill.  1:341. 
Chamaesyce  myrtillifoUa  (L.) 

Euphorbia  myrtillifoUa  Linn,  Syst.  ed.  X:io48. 
Chamaesyce  occidentalis  (Drew) 

Euphorbia  occidentalis  Drew  Bull.  Torr.  Club  16:152. 
Chamaesyce  ocellata  (Dur.  &  Hilg.) 

Euphorbia  ocellata  Dur.  &  Hilg.  Pacif.  R.  R.  Rep.  V:5:i5. 
Chamaesyce  paucipila  (Urban) 

Euphorbia  paucipila  Urban  Symb.  Antill.  5:389. 


April,  1916.  Euphorbiace^  —  Millspaugh  411 

Chamaesyce  petrina  (Wats.) 

Euphorbia  petrina  Watson  Proc.  Am.  Acad.  24:75. 
Chamaesyce  picachensis  (Brandeg.) 

Euphorbia  picachensis  Brandegee  Univ.  Calif.  Bot.  6:185. 
Chamaesyce  pileoides  (Millsp.) 

Euphorbia  pileoides  Millsp.  Field  Mus.  Bot.  2:62. 
Chamaesyce  podadenia  (Boiss.) 

Euphorbia  podadenia  Boiss.  DC.  Prodr.  15:40. 
Chamaesyce  polycarpa  (Benth.) 

Euphrobia  polycarpa  Bentham  Bot.  Sulph.  50. 
Chamaesyce  Pondii  (Millsp.) 

Euphorbia  Pondii  Millsp.  Contrib.  U.  S.  Natl.  Herb.  1:12. 
Chamaesyce  portulana  (Wats.) 

Euphorbia  portulana  Watson  Proc.  Am.  Acad.  24:75. 
Chamaesyce  pseudoserpyllifolia  (Millsp.) 

Euphorbia  psetidoserpyllifolia  Millsp.  Pittonia  2 187. 
Chamaesyce  puberula  (Fern.) 

Euphorbia  puberula  Fernald  Proc.  Am.  Acad.  ser.  2,  36:494. 
Chamaesyce  purissimana  (Millsp.) 

Euphorbia  purissimana  Millsp.  Proc.  Calif.  Acad.  ser.  2,  2:225. 
Chamaesyce  pycnanthema  (Engelm.) 

Euphorbia  pycnanthema  Engelm.  Max.  Bound.  2:188. 
Chamaesyce  radicans  (Moric.) 

Euphorbia  radicans  Moric.  in  Berland.  PL  Exsic. 

Euphorbia  serpens  radicans  Engelm.  Boiss.  DC.  Prodr.  15:30. 
Chamaesyce  radioloides  (Boiss.) 

Euphorbia  radioloides  Boiss.  DC.  Prodr.  15:45. 
Chamaesyce  ramosa  (Seaton) 

Euphorbia  ramosa  Seaton  Proc.  Am.  Acad.  ser.  2,  28:121. 
Chamaesyce  Rattanii  (Wats.) 

Euphorbia  Rattanii  Watson  Proc.  Am.  Acad.  20:272. 
Chamaesyce  rubrospenna  (Lotsy) 

Euphorbia  rubrosperma  Lotsy  Bot.  Gaz.  20:349. 
Chamaesyce  Rusbyi  (Greene) 

Euphorbia  Rusbyi  Greene  Bull.  Calif.  Acad.  57. 
Chamaesyce  scopulorum  (Brandeg.) 

Euphorbia  scopulorum  Brandegee  Univ.  Calif.  Bot.  4:184. 
Chamaesyce  Seleri  (Donn-Sm.) 

Euphorbia  Seleri  Donn-Smith  Bot.  Gaz.  27:441. 


412     Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

Chamaesyce  thymifolia  (Linn.) 

Euphorbia  thymifolia  Linn.  Sp.  PI.  454. 

Chamaesyce  tomentulosa  (Wats.) 

Euphorbia  tomentulosa  Watson  Proc.  Am.  Acad.  22:476. 

Chamaesyce  tonsita  nom.  nov. 

Euphorbia  polycarpa  hirtella  Boiss.  DC.  Prodr.  15:44,  non  E.  hirtella 

Boiss.  Cent.  Euph.  7. 
Chamaesyce  polycarpa  hirtella  Millsp.  Parish  Cat.  PI.  Salton  Sink  6. 

Chamaesyce  Torralbasii  (Urban) 

Euphorbia  Torralbasii  Urban  Sjnnb.  Antill.  i  :340. 

Chamaesyce  trachysperma  (Engelm.) 

Euphorbia  trachysperma  Engelm.  Mex.  Bound.  2:189. 

Chamaesyce  Turpini  (Boiss.) 

Euphorbia  Turpini  Boiss.  Cent.  Euph.  12. 

Chamaesyce  imibellulata  (Engelm.) 

Euphorbia  umbellulata  Engelm.  Boiss.  DC.  Prodr.  15:40. 

Chamaesyce  velleriflora  (Kl.  &  Gke.) 

Anisophyllum  velleriflorum  Kl.  &  Gke.  Tricocc.  28. 
Euphorbia  velleriflora  Boiss.  DC.  Prodr.  15:40. 

Chamaesyce  velligera  (Schaur.) 

Euphorbia  velligera  Schaur.  in  Linnea  20:728. 

Chamaesyce  vestita  (Boiss.) 

Euphorbia  vestita  Boiss.  Cent.  Euph.  7. 

Chamaesyce  villosior  (Greenm.) 

Euphorbia  villosior  Greenman  Proc.  Am.  Acad.  ser.  2,  32:297. 

Chamaesyce  Urbanii  nom.  nov. 

Euphorbia  villosula  Urban  Symb.  Antill.  1:340  (1899), 
non  Pax  Bot.  Yahrb.  19:118  (1894). 

Chamaesyce  Watsoni  (Millsp.) 

Euphorbia  Watsoni  Millsp.  Zoe  i  :347. 

Eumecanthus  Kl.  &  Gke.  Monat.  Akad.  Berl.  1859:248. 

Leaves  aequilateral,  usually  sparse  below,  the  upper  opposite; 
inflorescence  solitary  or  cymose;  bracteoles  obsolete;  seeds  ovoid-glob- 
ose, deeply  and  regularly  honeycomb-pitted  each  pit  with  a  secondary 
pit  or  papule  in  its  fundus. 

Type  species:  Euphorbia  ariensis  HBK. 

Leptopus  Kl.  &  Gke.  ibid  249,  non  Decne. 

Adenopetalum  Kl.  &  Gke.  ibid  250,  non  Turcz. 


April,  1916.  EuPHORBiACEiE  —  Millspaugh  413 

Eiunecanthus  Armourii. 

Euphorbia  Armourii  Millsp.  Field  Mus.  Bot.  1:28.     1895. 

The  range  of  this  species  is  Cozumel  Island  and  the  main  land  of 
Yucatan  from  Merida  to  Izamal,  San  Anselmo,  Chichan  Itza  and  Buena 
Vista  Xbac.  Schoti  76;  Millspaugh  108,  ijdg,  1570;  Gamner  Q75,  1821; 
Seler  3927,  4012;  Goldman  536. 

Eumecanthus  astroites  (Fisch.  &  Mey.). 

Euphorbia  astroites  F.  &  Mey.  Anim.  Ind.  Sem.  Petrop.  1845, 
Ann.  Soc.  Nat.  ser.  3,  5:371. 

Euphorbia  astroites  heterappendiculata  Millsp.  Field  Mus.  Bot.  i  :28. 
1895. 

The  range  of  this  species  is:  Mexico  at  Tampocoala,  Karwinsky; 
Izamal,  Millspaugh  64,  Gaumer  521;  and  Guatemala,  Kellerman  8038. 

Eumecanthus  gramineus  (Jacq.)  comb.  nov. 

Euphorbia  graminea  Jacq.  Stirp.  Amer.  151.     1763. 

This  species  has  a  broad  distribution  from  Chihuahua,  Mexico, 
southward  to  U.  S.  Colombia  and  Ecuador.  In  Yucatan  it  has  been  re- 
ttmied  from  Calotmul,  Izamal,  Tekax,  Temax,  Yaxcab  and  Chichan- 
kanab. 

Eumecanthus  xbacensis. 

Euphorbia  xbacensis  Millsp.  Field  Mus.  Bot.  1:374.     1898. 

Only  known  from  the  type  station,  Buena  Vista  Xbac,  Yucatan, 
Gaumer  1108,  "rare." 

The  other  North  American  species  are: 
Eumecanthus  ariensis  (Kth.)  Kl.  &  Gke.  Tricocc.  42.     1859. 

Euphorbia  ariensis  Kunth.  HBK.  Nov.  Gen.  2:46.     181 7, 

Eumecanthus  Benthamianus  Kl.  &  Gke.  idem. 

Eumecanthus  adiantoides  (Lam.) 

Euphorbia  adiantoides  Lam.  Encyc,  2:422. 
Leptopus  Hartwegii  Kl.  &  Gke.  Tricocc.  46. 

Eumecanthus  Bamesii 

Adenopetalum  Bamesii  Millsp.  Field  Mus.  Bot.  2:377. 

Eumecanthus  bifiurcatus  (Engelm.) 

Euphorbia  bifurcata  Engelm.     Mex.  Bound.  2:190. 

Eumecanthus  boerhaavifolius  (Boiss.) 

Euphorbia  boerhaavifolia  Boiss.  DC.  Prodr.  15:54. 

Eimaecanthus  bracteatus  (Kl.  &  Gke.) 

Adenopetalum  bracteatum  Kl.  &  Gke.  Tricocc.  48. 
Euphorbia  scabrella  Boiss.  DC.  Prodr.  15:55. 


414    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

Eumecanthus  delicatulus  (Boiss.) 

Euphorbia  delicatula  Boiss.  Cent.  Euph.  19. 
Eumecanthus  dioscoreoides  (Boiss.) 

Euphorbia  dioscoreoides  Boiss.  Cent.  Euph.  22. 
Eumecanthus  discolor  (Boiss.) 

Euphorbia  discolor  Boiss.  DC.  Prodr.  15:54. 
Eumecanthus  Francoanus  (Boiss.) 

Euphorbia  Francoana  Boiss.  Cent.  Euph.  22. 
Eumecanthus  Hoffmanni  (Kl.  &  Gke.) 

Adenopetalum  Hoffmanni  Kl.  &  Gke.  Tricocc.  47. 
Eumecanthus  digitatus  (Wats.) 

Euphorbia  digitata  Watson  Proc.  Am.  Acad.  26:146. 
Eumecanthus  calcicolus  (Fern.) 

Euphorbia  calcicola  Femald  Proc.  Am.  Acad.  ser.  2,  36:496. 
Eumecanthus  chiapensis  (Brandeg.) 

Euphorbia  chiapensis  Brandegee  Univ.  Calif.  Bot.  6:54. 

Euphorbia  tetradenia  Brandegee  exsic.  distrib. 
Eumecanthus  cofradianus  (Brandeg.) 

Euphorbia  cofradiana  Brandegee  Zoe  5:207. 
Eumecanthus  colimae  (Rose) 

Euphorbia  colimae  Rose  Contrib.  U.  S.  Natl.  Herb.  1:356. 
Etunecanthus  guadalajaranus  (Wats.) 

Euphorbia  guadalajarana  Watson  Proc.  Am.  Acad.  22:449. 
Eumecanthus  humayensis  (Brandeg.) 

Euphorbia  humayensis  Brandegee  Zoe  5:208. 
Eumecanthus  latericolor  (Brandeg.) 

Euphorbia  latericolor  Brandegee  Univ.  Calif.  Bot.  4:377. 
Eumecanthus  mexicanus  (Kl.  &  Gke.) 

Adenopetalum  tnexicanus  Kl.  &  Gke.  Tricocc.  50. 
Eumecanthus  microappendiculatus  (Lotsy) 

Euphorbia  microappendiculatum  Lotsy  Bot.  Gaz.  20:349. 
Eumecanthus  monanthus  (Wr.) 

Euphorbia  monantha  Wright  PI.  Cub.  Griseb.  1866. 
Eumecanthus  multisetus  (Bth.) 

Euphorbia  multiseta  Benth.  PI.  Hartw.  51. 
Eumecanthus  muscicolus  (Fern.) 

Euphorbia  muscicola  Femald  Proc.  Am.  Acad.  36:495. 
Eumecanthus  ocymoideus  (L.) 

Euphorbia  ocymoidea  Linn.  Sp.  PI.  453. 


April,  1916.  Euphorbiace^  —  Millspaugh  415 

Eumecanthus  pedunculosus  (A.  Rich.) 

Euphorbia  pedunculosa  A.  Rich.  Hist.  Cuba  11:198. 
Eumecanthus  physalifolius  (Boiss.) 

Euphorbia  physalijolia  Boiss.  Cent.  Euph.  19. 
Eumecanthus  pubescens  (Kl.  &  Gke.) 

Adenopetalum  pubescens  Kl.  &  Gke.  Tricocc.  49. 

Adenopetalum  irasuense  Kl.  &  Gke.  ibid.  50. 
Eumecanthus  segoviensis  (Boiss.) 

Euphorbia  segoviensis  Boiss.  DC.  Prodr.  15:58. 
Eumecanthus  sinaloensis  (Brandg.) 

Euphorbia  sinaloensis  Brandegee  Zoe.  5:208. 
Eumecanthus  subpeltatus  (Wats.) 

Euphorbia  subpeltata  Watson  Proc.  Am.  Acad.  25:146. 
Eumecanthus  subreniforme  (Wats.) 

Euphorbia  subreniforme  Watson  Proc.  Am.  Acad.  21:438. 
Eumecanthus  subsinuatus  (Boiss.) 

Euphorbia  graminea  subsinuata  Boiss.  DC.  Prodr.  15:54. 
Eimaecanthus  tenerus  (Wats.) 

Euphorbia  tenera  Watson  Proc.  Am.  Acad.  18:150. 
Eumecanthus  triphyllus  Kl.  &  Gke.  Tricocc.  43. 

Euphorbia  triphylla  Willd.  Herb.  9316. 

Euphorbia  scabrella  Boiss.  DC.  Prodr.  15:55. 
Eumecanthus  imabrosus  (Bertero) 

Euphorbia  umbrosa  Bertero  Spr.  Syst.  3:791. 
Eumecanthus  violaceus  (Greenm.) 

Euphorbia  violacea  Greenman  Proc.  Am.  Acad.  ser.  2,  33 :48o. 
Eumecanthus  xalapensis  (Kth.) 

Euphorbia  xalapensis  HBK.  Nov.  Gen.  2 :48 
Eumecanthus  zierioides  (Boiss.) 

Euphorbia  zierioides  Boiss.  DC.  Prodr.  15:58. 

Aklema  Rafin.  Fl.  Tell.  4:114.     1836-1838. 

Branches  articulate;  leaves  aequilateral,  temate  or  verticillate; 
stipules  glandular;  inflorescence  in  axillary  and  terminal  cymes,  corymbs 
or  panicles;  bracteoles  numerous,  plumose;  seeds  ovoid-globose,  shal- 
lowly  open  and  regiilar  pitted  with  no  secondary  pits. 

Type  species:  Euphorbia  nudiflora  Jacq. 

Euphorbia  Linn.  Sp.  PI.  453,  in  part.     1753. 

Alectoroctonum  Schlecht.  in  Linn.  19:252.     1847. 

Peccana  Rafin.  Sylv.  Tell.  114.     1838. 


4i6    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

Aklema  Gaumeri 

Euphorbia  Gaumeri  Millsp.  Field  Mus.  Bot.  1:372. 

The  only  known  range  of  this  species  is  Yucatan,  at  San  Anselmo 
and  Buena  Vista  Xbac,  Gaumer  iojq,  loyj,  1443. 
Aklema  Mayana 

Euphorbia  Mayana  Millsp.  Field  Mus.  Bot.  i  :304. 

Only  known  from  Yucatan,  at  Izamal  and  Buena  Vista    Xbac 
Gaumer  302,  lojg. 

The  other  North  American  species  are: 
Aklema  adinophylla  (Donn-Sm.) 

Euphorbia  adinophylla  Donn-Smith  Bot.  Gaz.  47:261. 
Aklema  apocynoides  (Kl.) 

Euphorbia  apocynoides  Klotzsch  Seem.  Bot.  Herald  99. 
Aklema  colletioides  (Bth.) 

Euphorbia  colletioides  Benth.  Stdph.  Voy.  163. 
Aklema  comonduana 

Euphorbia  comonduana  Millsp.  Proc.  Calif.  Acad.   ser.  2,  2:229. 
Aklema  cotiiilfolia  (L.) 

Euphorbia  cotinifolia  Linn.  Sp.  PI.  453. 
Aklema  elliptica  (Kl.  &  Gke.) 

Adenopetalum  ellipticum  Kl.  &  Gke.  Tricocc.  50. 

Euphorbia  saccharata  Boiss.  Cent.  Euph.  18. 
Aklema  Friderichthalii  (Boiss.) 

Euphorbia  Friderichthalii  Boiss.  DC.  Prodr.  15:61. 
Aklema  ligustrina  (Boiss.) 

Euphorbia  ligustrina  Boiss.  Cent.  Euph.  22. 
Aklema  Nelsonii 

Euphorbia  Nelsonii  Millsp.  Bot.  Gaz.  26:268. 
Aklema  nudiflora  (Jacq.)  Rafin.  Fl.  Tell.  4:114. 

Euphorbia  nudiflora  Jacq.  Coll.  3:180. 
Aklema  oaxacana  (R.  &  G.) 

Euphorbia  oaxacana  Robn.  &  Greenm.  Proc.  Am.  Acad.  32:37. 
Aklema  ovata  (Schlecht.) 

Alectoroctonum  ovatum  Schlecht.  in  Linn.  19:252. 

Euphorbia  Schlechtendahlii  Boiss.  Cent.  Euph.  18. 
Aklema  peganoides  (Boiss.) 

Euphorbia  peganoides  Boiss.  Cent.  Euph.  22. 
Aklema  petiolare  (Sims)   MiUsp.  Ann.  Mo.  Bot.  Gard.    2:43.     1915. 

Euphorbia  petiolaris  Sims.  Bot.  Mag.  t.  883. 


April,  1916.  Euphokbiace^e  —  Millspaugh  417 

Aklema  plicata  (Wats.) 

Euphorbia  plicata  Watson  Proc.  Am.  Acad.  21:438. 

Aklema  Scotana  (Schlecht.) 

Alectoroctonum  Scotanum  Schlecht.  in  Linn.  19:252. 
Euphorbia  Scotana  Boiss.  DC.  Prodr.  15:60. 

Aklema  tricolor  (Greenm.) 

Euphorbia  tricolor  Greenm.  Proc.  Am.  Acad.  33:479. 

Aklema  Xanti  (Engelm.) 

Euphorbia  Xanti  Engelm.  Boiss.  DC.  Prodr.  15:62. 

Euphorbia  gymnoclada  Engelm.  Proc.  Am.  Acad.  5:171,  non  Boiss. 

Aklema  yavalquahuitl  (Boiss.) 

Alectoroctonum  yavalquahuitl  Schlecht.  in  Linn.  19:252. 

Acalypha  flagellata  sp.  nov. 

A  dioecious  shrub,  2-5  meters  high,  glabrous  or  nearly  so,  with  terete, 
pithy  branches,  large  leaves  (7.5  x  12  cm.)  and  very  long  spikes  (15-35 
cm.). 

Stipules  leafy,  narrowly  ovate-lanceolate,  serrate,  apiculate,  1-2  cm. 
long;  petioles  6-7  cm.  long;  blade  palmately  5-veined,  ovate,  acimiinate, 
thin,  minutely  wrinkle-pitted  in  drying,  crenate-dentate,  each  tooth 
mucronate.  Infloresence  in  long,  simple,  lash-like,  axillary  spikes  often 
in  pairs  on  the  male  shrubs  though  generally  single,  rarely  one  monoecious 
spike  appears,  this  always  on  the  female  shrub.  Female  flowers  single, 
on  a  long,  filamentous  pedicel  (8-12  mm.);  pedicel  bibracteate,  pilose; 
calyx  4-parted  the  lobes  linear-lanceolate,  ciliate,  acute;  ovary  hairy  and 
stalked- tuberculate;  stylar  column  glanduliferous,  turbinate,  the  upper 
portion  cut  into  three  lobes  from  each  of  which  issues  a  fascicle  of  six 
long,  filiform,  transparent  stigmas.  Male  flowers  densely  fasciculate 
on  slender,  cylindrical  spikes,  very  short  pedicellate;  sepals  4,  scaphoid, 
minute,  caducous;  stamens  8,  filaments  ligulate,  ciliate.  Capsule  5  mm. 
diam.  deeply  tricoccous  the  cocci  globular,  strongly  marked  by  the  line 
of  dehiscence,  scurfy  and  stalked-glanduliferous-tuberculate  beneath; 
seed  red-brown,  globose,  apiculate,  1.2  mm.  diameter,  minutely  papil- 
late-carunculate,  the  surface  minutely  puncticulate. 

Type  station  Buena  Vista  Xbac,  Yucatan,  Gaunter,  September  1896, 
iioy  (Type  in  herb.  Field  Museum,  cat.  no.  438,224).  Also  gathered  by 
Dr.  Gaumer  at  Chichankanab  2iy8,  21'jg. 

Acaljrpha  simplicissima  sp.  nov. 

An  erect,  simple,  slender  annual  about  4.5  cm.  high.  Stem  terete, 
crispidulous-hairy.     Petioles  filiform  about  the  length  of  the  thin,  ovate, 


4i8    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

acute  leaves;  leaves  3  x  1.5-4  x  2.5  cm.,  glabrous,  palmately  5-nerved  at 
the  rounded  base,  margin  slightly  crenate-dentate.  Inflorescence  axil- 
lary, the  female  flowers  on  long  (3-6  cm.),  pedunculate,  wiry,  10-18- 
bracted,  open  spikes;  the  male  on  a  short,  rudimentary,  capitulate  spike 
separate  in  the  same  axils.  Bracts  of  the  female  flowers  6-7  mm. 
ovate,  narrowed  to  the  sessile  base,  acute,  the  margin  few-serrate, 
ciliate.  Female  flowers  usually  3  to  the  bract,  sessile;  calyx  3-parted, 
lobes  narrowly  lanceolate;  styles  6,  fibrillate,  about  four  times  the 
length  of  the  ovary.  Male  flowers  10  or  more  in  a  dense,  pedunculate 
head;  calyx  of  four  linear  lobes  with  transparent,  chaff-like  margins. 
Capsule  strigose-hairy;  seed  ashen,  smooth,  ovoid-apiculate,  1.2x1  mm. 
Yucatan,  at  Progreso  in  a  shady  coppice.  Gaunter  1182  (Type  in 
herb.  Field  Museum,  cat.  no.  438,255),  and  at  Chichankanab,  Gaumer 
2225. 

Croton  Gaumeri  sp.  no  v. 

Dioecious,  fruticose,  open  stellate-pubescent.  Leaves  thin,  lanceo- 
late-acuminate, 3-4.5  X  .75-1.50  cm.;  petioles  one-third  the  length  of  the 
blade;  male  shrubs  with  leaf  margins  distantly  glandulose,  on  some 
individuals  these  glands  become  long-stalked  though  by  no  means  on  all 
nor  on  all  leaves  on  any  one  shrub.  Leaves  (male)  papillate  on  both 
surfaces,  the  margin  generally  distantly  glandulose  and  often  stalked- 
glandular  especially  near  the  base,  in  young  leaves  both  surfaces  are 
openly  stellate-pubescent;  stipules  triangular,  seldom  found  at  the  older 
leaves;  leaves  on  female  shrubs  scattered  stellate-pubescent  above,  more 
closely  and  prominently  so  beneath.  Inflorescence  terminal,  in  long, 
slender  spikes  floriferous  above,  flowers  pedicellate,  bracts  minute,  the 
male  spikes  sHghtly  pubescent  the  female  decidedly  so  and  with  long, 
straight  hairs  mixed  with  the  closely  appressed  stellate  ones;  male 
flowers:  caly:x  stellate-hairy,  4-lobed,  the  lobes  ovate,  acute,  rudimentary 
petals  4,  lanceolate,  stamens  about  20,  filaments  glabrous;  female 
flowers:  pedicels  half  the  length  of  the  calyx,  calyic  stellate-pubescent, 
5-lobed,  lobes  oblong-lanceolate,  acute,  margin  glandular,  rudimentary 
petals  5,  alternate  with  the  caljrx  lobes,  narrowly  ligulate  and  tipped 
with  a  globular  gland,  appearing  like  stamens,  styles  3  divided  to  the 
base,  digitately  4-lobed,  lobes  cylindrical,  incurved  at  the  tip.  Ripe 
capsule  about  5  mm.  diam.,  smooth  as  if  varnished  and  bearing  a  few 
isolated  stellate  hairs;  seed  scaraboid,  smooth  and  shining  greenish- 
brown,  3.5  X  2.8  mm.,  canincle  strongly  reniform,  thin,  waxen. 

Yucatan,  vicinity  of  Izamal.  Unnumbered  specimens  collected  by 
Dr.  Gaumer  in  1894  (Type  in  herb.  Field  Museum  cat.  no.  187,265). 
Two  sheets  of  twigs  of  male  shrubs  appear  in  the  series  of  Dr.  Gaumer's 


April,  1916.  Euphorbiace^  —  Millspaugh  419 

Izamal  collection  of  1888  deposited  in  Kew  Herbarium;  duplicates  of 
these  in  herb.  Field  Museum  bear  its  cat.  nos.  181,499  ^nd  181,500. 

Croton  glandulosepalus  sp.  nov. 

A  tall,  white-barked  shrub  with  long,  terminal  spikes  and  thin, 
ovate-lanceolate  leaves  clustered  toward  the  tips  of  the  branchlets 
leaving  the  branches  bare.  Leaves  ovate-lanceolate,  sparingly  ap- 
pressed-stellate,  acute  to  aciuninate,  apiculate,  4-6  x  2-3  cm.,  3-nerved 
at  the  base,  both  surfaces  dotted  with  scattering,  fine,  slender,  stellate 
hairs  which  nearly  disappear  when  the  leaves  are  fully  mature;  petioles 
slender,  about  one-third  the  length  of  the  blade,  puberulous;  stipules 
aristate,  about  5  mm.  long.  Inflorescence  monoecious,  terminal  in 
elongate,  rather  openly  flowered  spikes  with  large,  ovate  bracts  bear- 
ing a  number  of  long-stalked,  ciliate  glands  on  the  margin.  Male 
flowers  short-pedicellate  enclosed  by  the  scaphoidally  enveloping  bracts, 
caly^  4-lobed,  woolly  with  stellate  hairs,  lobes  ovate,  petals  4,  thin, 
ovate-scaphoid,  glabrous  or  nearly  so;  stamens  10,  filaments  short 
(about  the  length  of  the  anthers),  glabrous,  anthers  large,  innate.  Fe- 
male flowers:  thick  pedicelled  and  densely  white-woolly  below;  calyx 
4-lobed  the  lobes  ovate-lanceolate,  sarcous,  exteriorly  invested  with  a 
dense  mass  of  red,  stalked-globular  glands  and  enclosing  the  pistil 
closely;  petals  small,  flabelliform,  margin  stalk-glandular;  ovary  densely 
white-stellate  woolly;  styles  3,  each  4-cleft  to  the  base,  the  filamentous 
branches  incurled  at  their  tips.     Capsule  and  seed  unknown. 

Yucatan,  common  on  the  open  plain  from  Progreso  to  Merida, 
Gaumer  11 54  (Type  in  herb.  Field  Musetun  cat.  no.  438,492).  Also  re- 
turned by  Dr.  Gatmier  from  Buena  Vista  Xbac,  1046  and  from  Chichan- 
kanab  2204. 

Croton  malvavisciifolius  sp.  nov. 

Shrub  with  terete,  ferrugineous  branches,  large  bi-colorate,  irregular- 
ly and  doubly  serrate-dentate  leaves,  and  short  monoecious  terminal 
spikes.  Stems  rusty  stellate-hairy  the  central  ray  of  the  stellae  erect 
and  acicular  the  base  appressed  to  the  bark;  stipules  ligulate;  petioles 
somewhat  less  than  one-third  the  length  of  the  leaf  blade.  Leaves  broad- 
ly ovate,  7-14x5-10  cm.,  acute  to  acuminate,  palmately  7-nerved, 
dark-brown,  papillate  and  scattered  stellate-hairy  above,  light-green 
and  densely  felted  with  stellate  hairs  beneath,  each  leaf  bearing  2 
fimnel-shaped,  long,  stalked  glands  at  the  petiole,  base  strongly  cordate, 
apex  acute,  margin  irregularly  doubly-serrate,  dentate  with  a  stalked, 
funnel-shaped  gland  in  the  sinus  of  each  of  the  larger  dentations.  In- 
florescence monoecious,  terminal,   short,  female  below  male  above. 


420    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

densely  ferrugino-stellate  pubescent.  Female  flower  short-pedicellate, 
bicolorate  (dark  within  light  without)  color  and  pubescence  a  counterpart 
of  that  of  the  leaves;  cal3rx  lobes  5,  spatulate,  deeply  3-5-dentate  toward 
the  apex;  ovary  ovate,  rusty-hairy,  styles  3  each  bifid  to  the  base,  the 
branches  long  and  cyHndrical,  with  flattened,  incoiled  apices.  Male 
flower  bicolorate  as  in  the  female,  pedicellate;  calyx  5-lobed  the  lobes 
ovate,  obtuse;  petals  5,  obovate-spatulate,  thin,  red-brown;  stamens  6, 
filaments  with  a  tuft  of  hairs  at  the  base.  Capsule  densely  stellate- 
pubescent,  enclosed  in  the  persistent  calyx;  seed  flatly  scaraboid,  3x2 
mm.,  caruncle  very  thin,  papyraceous. 

Yucatan,  at  Yot  Tzonot,  Gaumer  ijiq  (Type  in  herb.  Field  Museum 
cat.  no.  438,278). 

Tragia  {Eutragia)  yucatanensis  sp.  nov. 

An  erect,  shrubby  climber,  i  meter  high.  Stem  terete,  puberulent, 
branches  virgate;  stipules  small,  cordate-lanceolate,  acute,  closely  ap- 
pressed  to  the  stem;  petioles  one-third  to  one-half  the  length  of  the  leaf 
blade;  leaves  ovate-lanceolate,  3-6  x  2-4  cm.,  5-nerved,  somewhat 
cordate  at  the  base,  acuminate,  dentate,  scattered-hairy  on  both  sur- 
faces. Inflorescence  in  few  flowered,  slender,  short,  simple  racemes 
one-half  to  three  cm.  long,  inserted  opposite  the  upper  leaf  petioles,  the 
female  solitary  near  the  base  of  the  raceme,  the  male  few,  terminal; 
bracts  minute,  sessile,  lanceolate,  acute,  entire.  Male  flowers  pedicelled; 
pedicel  about  equaling  the  width  of  the  QolyK.,  pilose,  somewhat  thick- 
ened below;  calyx  3-parted,  lobes  ovate,  acute,  glabrous;  stamens  3, 
filaments  turgid-bulbous  below;  anthers  ovate;  rudimentary  ovary 
wanting.  Female  flowers  pedicelled;  pedicel  about  one-half  the  width 
of  the  calyx;  cdlys.  segments  6,  ovate,  acute;  ovary  3-celled,  densely 
acicular-hairy ;  style  turgid,  trifurcate  to  the  middle,  the  branches  tightly 
recurved  at  the  tips.  Capsule  densely  invested  with  long,  white,  acicu- 
lar  hairs;  seed  globose,  2.3  mm.  diameter,  yellow,  mottled  in  irregular 
anastomosing  splotches  and  stippled  with  minute  dots  of  red-brown. 

Yucatan,  in  woodlands  at  Chichankanab,  Gaumer  2154  (Type  in 
herb.  Field  Museum  cat.  no.  438,347) ;  and  at  San  Anselmo,  1931.  This 
species  and  Tragia  nepetaefolia  are  called  P  o  p  o  x  by  the  Mayas. 


April,  1916.  Alacran  Reef  —  Millspaugh  421 


VEGETATION   OF   ALACRAN   REEF 

The  Alacran  Reef  forms  the  northeastemmost  danger  on  the  Cam- 
peche  Bank,  in  the  Gulf  of  Mexico,  75  miles  N.  by  E.  ]4  E.  from  Sisal 
Fort  on  the  Yucatan  mainland.  The  position  of  Perez  Cay,  its  most 
southern  islet,  is  latitude  22°33'36"N.;  longitude  89°4i'45"W. 

The  general  form  of  the  reef  is  semilunar,  convex  to  the  NE.,  the 
straight  western  face  trending  NNW.  >^  W.  14  miles,  its  greatest  width 
being  8  miles.  The  weather,  or  NE.  side,  is  composed  of  a  compact 
mass  of  coral,  dry  in  many  places,  over  which,  on  all  parts,  the  sea 
breaks  with  violence.  The  lee  side,  similar  to  all  reefs  of  this  character 
in  these  seas,  is  composed  of  detached  coral  heads,  easily  seen  in  the 
clear,  deep  water  of  the  bank. 

At  the  SE.  extreme  of  the  reef  are  three  small,  sandy  cays  rising 
not  over  5  ft.  high.  These  are  known  as  Perez,  Pajaros  and  Chica  Cays. 
Pajaros  and  Chica  lie  yi  mile  apart  800  yds.  from  the  SE.  extremity  of 
the  reef,  Perez  l3dng  about  a  mile  westward  from  them.  Between  the 
eastward  pair  and  Perez  there  is  an  excellent  reef -harbor  for  small  ves- 
sels; formerly  4  fathoms  could  be  carried  into  this  harbor  but  at  the 
time  of  oiur  visit  it  held,  in  a  few  places,  but  a  precarious  2  fathoms. 

NW.  by  N.,  3  miles  from  Perez,  is  a  small  cay,  about  8  feet  high, 
which  we  named  Allison  Island,  and  about  the  same  distance  southward 
of  the  NW.  end  of  the  reef  is  another  islet,  about  10  feet  high,  which  we 
named  Utowana  Cay,  though  we  were  unable  to  land  upon  it  on  account 
of  sea  conditions  at  the  time  of  our  approach. 

The  Alacran  Bank  is  everywhere  so  steep-to  that  there  is  no  safe 
anchorage  for  larger  vessels,  not  even  on  the  lee  side,  the  only  clear 
landing  place  is  on  the  inner  side  of  Perez  Cay  at  the  mouth  of  the  reef- 
harbor  mentioned. 

The  approach  to  this  shoal,  when  working  to  windward,  requires 
more  than  ordinary  attention  as  the  soundings  near  it  do  not  give  suf- 
ficient warning  and  the  islets  are  invisible  if  the  sea  be  high.  As  the 
Yacht  Utowana  (which  the  owner  and  master  Mr.  AUison  V.  Armour 
allowed  to  approach  the  reef  on  the  voyage  of  which  I  had  the  honor  of 
being  his  guest)  arrived  in  the  neighborhood,  the  captain  slowed  the 
vessel  down  and  sent  a  lookout  to  the  cross  trees.  Though  we  proved  to 
be  but  about  two  miles  from  Allison  Island  yet  nothing  could  be  seen 
of  the  reef  until  a  cloud  of  frigate-birds*  arose  indicating  its  presence. 

As  the  reef  lies  directly  within  the  sweep  of  the  Gulf  Stream  in  the 
youth  of  its  course  we  judged  that  it  might  receive  aquavectent  seeds 
*Fregata  aquila  (Linn.). 


422    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 


^ 


i/toivcma  Cay 


•. --•    •.-.'  I 


v.^^ 


r 


ALACRAIST 


HEEF 


<^Mlison  Isl. 


\ 


"> 


\ 


v^v 


\     A 


X    A 
\  A 


J — a. 


j>         oo  -         rw.f 


April,  1916.  Alacran  Reef  —  Millspaugh  423 

from  the  east  coast  of  Yucatan,  Cozumel  Island,  and  the  Caribbean 
mainland;  and,  on  that  account,  desired  to  record  its  vegetation  at  this 
time  (March,  1899). 

At  the  time  of  the  charting  of  this  reef  by  the  British  Admiralty,  in 
1842,  Pajaros  and  Chica  were  "bare  sand  spits  devoid  of  vegetation;" 
Perez,  the  largest  cay,  and  Allison  Island,  had  upon  them  "grass* 
and  samphiret  only."  This  record  we  are  boimd  to  accept  as  a  careful 
and  comprehensive  one  for  the  reason  that  on  account  of  the  dangerous 
character  of  the  reef  it  was  essential  that  it  should  be  accurately  de- 
scribed, even  to  its  vegetation.  Accumulated  obser\'^ations  from  1842  to 
1896  added  "brushwood"  to  the  southern  cays  and  "bushes"  to  Allison 
Island,  though  no  traces  of  bushes  were  to  be  found  on  the  latter  at  the 
time  of  our  visit;  this  indicates  one  of  two  facts:  either  that  they  had 
been  removed,  even  to  their  roots,  by  fishermen  for  firewood,  or  by 
natural  erosion.  The  age  of  the  stunted  trees  termed  "brushwood," 
as  I  have  recorded  further  on  under  Siuiana  maritima,  proves  that 
"brushwood"  was  not  on  Perez  in  1842  at  the  time  of  the  Admiralty 
survey. 

In  searching  out  the  vegetation  of  the  cays  a  most  careful  survey 
was  made.  Each  cay  was  minutely  examined  by  our  party  over  every 
square  foot  of  its  surface,  I  am  certain  that  no  species  escaped  our  at- 
tention. A  detailed  indication  of  each  of  the  eighteen  species  fotmd  is 
given  in  conjunction  with  the  map. 

The  discovery,  on  these  islets,  of  three  species  new  to  science,  with 
the  proof  that  they  have  evolved  within  the  known  and  definite  period 
of  57  years,  is  a  fact  impressive  as  it  is  important. 


Perez  Island,  the  largest  cay,  rises  about  5  feet  in  height,  its 
beach  being  more  or  less  abrupt  on  the  west  and  gradually  sloping  on  the 
east  or  inner  coast  line.  It  is  about  2550  feet  in  length  and  about  325 
feet  wide  as  its  broadest  point.  Its  surface  is  entirely  coral  sand  except 
for  a  small  cairn  of  weathered  coral  heads  as  indicated  below. 

I  was  informed  that  a  few  years  previous  to  our  visit  a  party  of  men 
was  left  on  this  cay,  by  the  Mexican  Government,  w4th  material  for  the 
purpose  of  constructing  a  beacon.  Their  supplies  gave  out  and  no  more 
were  sent  to  them.  They  were  finally  rescued  by  a  fishing  vessel  and 
brought  to  the  mainland  in  a  dying  condition.  One  died  before  the 
rescue  and  was  buried  at  the  north  end  of  the  cay.  Several  holes  in  the 
cay  attested  to  thejpiteous  attempts  of  these  neglected  men  to  secure 

*Sporobolus  virginicus. 
tSesuvium  portulacastrum. 


424    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

drinkable  water.  From  the  largest  of  these  holes  at  the  northern  third 
of  the  islet  a  mound  of  weathered  coral  heads  was  heaped  during  its 
excavation.  This  forms  the  only  prominence  on  the  surface  of  the  cay 
and  is  the  habitat  of  a  growth  of  cactus  (Opuntia  Toona)  the  seed  of 
which  was  doubtless  dropped  here  by  some  resting  bird.  In  like  manner 
a  seed  dropped  from  an  arm  of  the  little  wooden  cross  marking  the  grave's 
head  accounts  for  the  only  plant  of  Scaevola  Lobelia.  The  "wooden, 
pyramidal  framework  30  feet  high"  erected  by  this  party  at  the  south 
end  of  the  islet,  mentioned  in  the  U.  S.  Coast  Pilot  for  1896,  had  long 
since  disappeared  as  kindling  for  fishermen's  cuddy  fires. 

The  main  extent  of  the  surface  is  densely  clothed,  about  8  in.  deep, 
with  a  level  carpet  of  Sesuvium  portulacastnun  broken  in  only  three 
places  by  small  patches  of  Sporobolus  virginicus  associated,  in  one  in- 
stance, with  Portulaca  oleracea;  in  another  with  Boerhaavia  repens; 
and  in  a  third  with  Flaveria  linearis  which  has  scattered  in  among  the 
Sesuviimi  as  mentioned  under  the  consideration  of  this  species.  The 
whole  of  the  south  end  is  clothed  with  a  nearly  pure  growth  of  the  Sporo- 
bolus in  which  a  few  plants  of  Atriplex  cristata  have  foimd  a  rooting. 

The  whole  west,  or  weather,  bank  is  lined  with  a  fringe  of  Suriana 
which  exists  without  the  admixture  of  any  other  species  for  the  northern 
two-thirds  of  its  length;  to  the  southward  a  few  shrubs  of  Toumefortia 
intermingle  and  still  further  south  six  climips  of  Conocarpus.  Between 
the  Suriana  fringe,  on  the  top  of  the  bank,  and  the  wave  line  of  the 
narrow  strand  at  the  southern  third,  a  scattering  growth  of  the  new 
Caldle,  intermixed  further  southward  with  Chamaesyce  buxifolia,  com- 
pletes the  flora  of  the  west  shore.  The  interspersed  species  of  the  toe 
of  the  stocking-shaped  islet,  where  boobies*  evidently  ahght  during 
fishing,  were  Cenchrus  carolinianus,  Portulaca  oleracea  and  one  individ- 
ual each  of  Tribulus  alacranensis  and  Cyperus  brunneus. 

For  some  reason  neither  the  booby  nor  the  frigate-bird,  prevalent 
on  the  other  cays,  nest  on  this  islet.  The  reason  is  not  apparent  to  me 
tmless  mayhap  the  presence  of  the  complete  fringe  of  shrubbery  on  the 
west  shore  may  prove,  in  some  way,  inimical  to  them. 

Pajaros  (Bird)  Cay,  the  southeast  islet  of  the  shoal,  is  a  low,  pure 
sand  microcosm,  rounded  to  the  center,  with  the  eastern  or  weather 
shore  line  slightly  banked  and  the  western,  or  inner,  beach  sloping.  It  is 
about  650  X  325  feet  in  extent. 

The  distribution  of  plant  species  on  its  surface  is  in  exact  duplication 
of  that  on  Perez;  Cakile  and  Chamaesyce  on  the  beach  line  of  the 
weather  shore  and  no  plant  life  on  the  marge  of  the  sloping  strand. 

*Sula  cyanops  (Sunderval). 


The  Grave  on  Perez  Island. 


A  Booby  on  its  Nest  Composed  entirely  of  the  Stems  of  tribulus  Alacranensis. 


Northwest  End  of  Chica  Island  Carpeted  with  Sesuvium. 

Horizon. 


Looking  toward  Pajaros  on  the 


April,  1916.  Alacran  Reef  —  Millspaugh  425 

Two  shrubs  only  had  secured  a  footing  on  this  cay,  one  each  of  Conocar- 
pus  and  Toumefortia.  Scattered  amongst  the  dense  growth  of  Sesuvium 
was  found  a  number  of  clumps  of  the  new  Cenchrus,  forming  its  only 
habitat,  and  one  climip  each  of  the  new  Tribulus,  Portulaca  oleracea 
and  Atriplex  cristata.  In  the  clear  sand  beyond  the  Sesuvium  at  its 
northernmost  margin  was  another  colony  of  the  new  Cenchrus. 

Chica  (Little)  Island  is  another  low,  pure  sand  cay,  fusiform  in 
outline,  575  x  325  feet  in  extent. 

On  this  islet  the  disposition  of  the  Sesuvium  and  Sporobolus  areas 
is  reversed  in  comparison  with  the  other  two  cays,  while  the  scattering 
other  species  are  interspersed  with  the  Sporobolus  colony  instead  of  the 
Sesuviiun.  In  this  the  clothing  of  the  islet  is  quite  similar  to  that  of  the 
foot  of  Perez  and  shows  plainly  that  it  forms  a  resting  place  for  web- 
footed  birds.  Here  the  new  Tribulus,  Atriplex  cristata  and  the  Chamae- 
syce  grow  in  profuse  masses  while  the  new  Cakile  maintains  its  charac- 
teristic habitat  on  the  weather  beach  line. 

Allison  Island,  three  rmles  from  the  other  cays  described,  differs  in 
several  respects  from  the  other  three.  First :  it  lies  east  and  west — the 
others  essentially  north  and  south;  second:  its  entire  coast  line  is  weather 
shore;  i.  e.,  abrupt  and  eroded  above  a  narrow  strand,  except  a  small 
portion  of  its  western  extremity  which  is  somewhat  spit-like;  third: 
it  is  considerably  higher  (about  8  ft.)  and  flat  Hke  a  table-land.  Its 
dimensions  are  about  1000  x  275  feet. 

Notwithstanding  the  fact  that  this  islet  is  comparatively  large  it 
nevertheless  gives  place  to  but  six  plant  species.  Its  "grass  "  and  "sam- 
phire "  colonies  are  pure,  as  on  the  other  islets.  The  largest  bird  colonies 
of  all  are  on  this  cay,  in  fact  it  is  almost  wholly  a  nidulation  ground. 
Boobies  appropriate  the  grass  colony  and  frigate-birds  the  Sesuvium 
tract.  It  is  on  this  cay  that  Tribulus  alacranensis  evolved,  its  presence 
on  the  other  cays  being  a  matter  of  transplantation  through  its  burs 
having  adhered  to  the  feet  of  the  booby.  The  species  exists  in  dense 
colonies  amongst  the  Sporobolus,  and  it  is  of  its  ligneous  stems  and 
branches  that  the  boobies  build  their  nests.  The  only  colony  of  Philox- 
erus  vermicularis  on  the  cays  is  here  in  the  Sporobolus,  as  well  as  a  widely 
scattering  growth  of  the  Chamaesyce.  Again  the  new  Cakile  lines 
itself  along  the  weather  strand  but  only  on  the  weathermost  side. 

Utowana  Cay,  which  we  sighted  but  were  unable  to  attain,  is  the 
northernmost  islet  of  the  group.  Through  the  glass  its  surface  appeared 
very  like  that  of  Allison  Island.  As  it  lies  north  and  south  much 
further  within  the  bank  of  the  reef  than  any  of  the  other  cays  its  vegeta- 


426    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

tion  should  prove  particularly  interesting,  we  were  deeply  disappointed 
that  the  risk  was  too  great  to  allow  of  the  yacht  being  brought  near 
enough  to  grant  us  a  landing. 

THE   PLANT  SPECIES 

1.  Sesuvium  portulacastrum  (L.)  Linn.     Syst.  ed.  X,  1058. 

This  is  by  far  the  prevalent  species  of  the  cays  and  here  forms  the  most 
extensive  and  succulent  masses  I  have  ever  seen.  It  clothes  the  easterly 
areas  of  all  the  islets  with  a  dense  carpet  about  eight  inches  thick.  Only 
a  few  individuals  were  in  flower  at  the  time  of  our  visit.  As  the  stems 
of  this  plant  are  fragile;  broken  pieces  long-lived;  and  as  such  pieces 
put  forth  strong  and  viril  rootlets  in  water,  I  am  inclined  to  place  its 
dispersional  character  as  bodily  aquavectent.  It  is  possible  also  that 
ripe  fruits  may  be  transported  in  like  manner.  Its  characters  are  strong- 
ly against  avevectence. 

2.  Sporobolus  virginicus  (L.)  Kunth.  Rev.  Gram.  1:67. 

The  second  species  in  extent  on  the  cays.  This  grass  appears  to 
spread  only  where  some  influence  has  checked  the  growth  of  the  Sesuv- 
ium, as  for  instance  the  tramping  about  of  the  birds  or  the  digging  of 
water-holes  and  the  constructive  efforts  of  the  men  who  built  the  beacon 
structure  on  the  south  end  of  Perez.  This  is  so  pronounced  a  fact  that 
a  glance  at  the  distinguishing  colors  on  the  maps  shows  by  the  yellow, 
for  Sporobolus,  the  location  of  the  three  water-holes  and  the  area  of 
the  beacon-site;  while  the  yellow  on  the  maps  of  the  other  cays  demarks 
perfectly  the  booby  nesting  areas  —  always,  for  some  reason  westerly 
on  the  islets.  Note,  by  the  same  token,  that  the  booby  sections  are 
always  where  the  land  slopes  gently  to  spit-like  extremities.*  The  booby 
never  nests  near  the  weather,  or  abrupt,  shore. 

From  its  habitat  it  is  evident  that  Sporobolus  is  aquavectent;  it  has 
however  only  been  found,  on  the  Yucatan  mainland,  in  protected  situa- 
tions near  lagoons,  whence,  if  its  Alacran  soiu*ce  is  the  mainland,  its 
spikes  must  first  have  been  blown  to  the  sea  before  its  real  transportation 
began. 

3.  Suriana  maritima  L.  Sp.  PL  284. 

A  fringe  of  low  shrubs  of  this  species  lines  the  top  of  the  ''bank" 
of  the  western  or  weather  shore  of  Perez  Island.  The  growth  is  pure  in 
the  northern  two-thirds  of  the  fringe,  the  southern  third  has  an  inter- 
mixture of  a  few  clumps  of  Toumefortia  and,  further  south,  of  Conocar- 
pus. 

*  In  order  that  the  fledglings  may  get  to  the  water  and  back  to  the  nest? 


April,  1916.  Alacran  Reef  —  Millspaugh  427 

In  order  to  check  up  the  record  of  the  Admiralty  survey  I  cut  down 
the  two  apparently  oldest  shrubs  and  made  cross  sections  of  the  trunks.* 
In  so  far  as  the  annual  rings  may  determine  they  proved  to  be  25  and 
30  years  old  respectively.  Should  the  rings  prove  a  faulty  record  the 
error  would  be  in  favor  of  a  shorter  period  of  growth,  it  is  therefore 
certain  that  the  shrubs  did  not  exist  there  at  the  time  of  the  survey,  the 
notes  of  which  state:  "Grass  and  samphire  only."  One  shrub,  judged 
to  be  not  over  four  years  old,  grew  on  the  southern  shore  of  Chica. 

At  the  period  of  ripened  fruits  the  fruiting  twigs  of  this  species  be- 
come quite  brittle  and,  as  the  plant  frequents  the  immediate  sea  shore, 
these  twigs  are  often  broken  off  by  heavy  winds  and  blown  into  the  sea. 
That  they  float  away  and  are  later  washed  ashore  on  the  crests  of  waves 
was  apparent  in  the  "wash  line"  on  the  weather  side  of  Perez  where  I 
found  a  large  quantity  of  fruiting  twigs  newly  come  ashore.  This 
leaves  no  doubt  of  the  species  being  bodily  aquavectent. 

4.    Cakile  alacranensis  Millsp.  Field  Mus.  Bot.  2:130. 

This  new  species  of  the  shoal  differs  from  all  others  known  in  its 
short  silique  bearing  four  channelled  lines  instead  of  8  or  more  (angles 
in  most  species);  in  its  upper  joint  being  globose-apiculate  and  very 
turgid;  in  its  infundibuliform  lower  joint  which  is  but  httle  more  than  a 
swelling  of  the  pedicel,  and  in  having  its  seeds  dotted  with  brownish 
punctae.  The  leaves  are  yellowish-green,  spatulate-lanceolate  tapering 
to  a  partly  clasping  petiolar  base,  and  entire  or  rarely  slightly  crenate  or 
crenate-dentate  at  the  apex. 

This  species  grows  upon  the  north  strand  of  Allison  Island;  on  the 
north  weather  strand  of  Chica  and  Pajaros;  and  on  the  southern  half  of 
the  weather  strand  of  Perez.f  While  the  plants  from  both  Perez  and 
Pajaros  are  large  fruit  producers  they  have  a  sickly  yellow  appearance 
compared  with  the  fresh,  cool  green  of  those  of  Chica.  It  is  evident  that 
the  original  habitat  of  this  species  is  either  Allison  Island,  or  possibly 
unexplored  Utowana  Cay,  as  the  distribution  of  the  plants  on  the  south- 
ern cays  is  quite  apparently  more  recent. 

It  appears  to  me  that  this  species  is  evolving  for  the  piu-pose  of 
more  highly  developed  aquavectence.  The  upper,  or  floating  joint,  is 
certainly  developing  far  more  rapidly  than  the  lower,  or  fixed,  joint  of 
the  fruit :  the  upper  at  the  expense  of  the  lower. 

Distributionally  the  upper  joint  of  the  fruit  is  aquavectent  while  the 
lower,  being  fixed  upon  the  rhachis  and  on  that  account  not  adapted  to 

*These  sections  are  mounted  on  the  herbarium  sheets  of  the  species  from  this 
island  in  the  Museum  herbariiun. 

tThe  treatment  of  Cakile  in  Field  Mus.  Bot.  2:43  and  2:128-130  to  the  contrary 
not  withsta  nding . 


428    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

dispersion,  is  evidently  intended  to  perpetuate  the  species  only  in  the 
habitat  of  the  parent  plant. 

5.  Chamaesyce  buxifolia  (Lam.)  Small. 

This  common  seaside  Euphorbia  is  found,  on  the  booby  rest-strands 
only,  on  all  the  islets.  It  does  not  associate  (except  on  Pajaros)  with 
the  aquavectent  Cakile  nor  with  other  aquavectent  species. 

The  seed  coat  of  this  species  swells  greatly  and  becomes  mucilag- 
inous when  moist.  This  causes  the  seeds  to  adhere  to  the  wet  webs  of 
swimming  birds  when  resting  along  the  shore.  Thus  the  plants  are 
widely  distributed  on  the  island  strands  of  the  Gulf  of  Mexico  region. 

6.  Tribulus  alacranensis  MiUsp.  Field  Mus.  Bot.  2:54. 

This  new  species  differs  from  its  probable  parent,  T.  maximus  of  the 
mainland,  in  its  long,  heavy,  tangled  and  jointed  Ugneous  stems  and 
branches;  its  mass  growth;  its  larger  flowers  and  smaller  fruits;  its 
4-6-spined  carpids;  and  in  its  leaves  being  densely  woolly  on  both  sur- 
faces. The  original  habitat*  of  this  species  is  apparently  the  Sporo- 
bolus  colony  of  Allison  Island,  where  the  boobies  construct  their  nests 
wholly  of  its  stems  and  branches. 

The  dispersional  character  of  the  species  is  avevectent,  through  the 
sharp-spined  fruits  clinging  to  the  webbed  feet  of  swimming  birds. 

7.  Tournefortia  gnaphalodes  R.  Br.  Prod.  496. 

This  common  sea  shore  shrub  of  the  Antillean  region  has  found  a 
place  of  growth  amongst  the  Siuiana  shrubs  at  the  southern  extension 
of  the  fringe  on  Perez.  One  shrub  only  was  just  appearing  on  the  south 
shore  of  Pajaros.  The  specimens  appear  to  differ  in  no  respect  from 
those  of  the  mainland. 

As  with  Stiriana  the  fruiting  branch  tips  of  this  species  break  off 
dtuing  high  winds  and  are  often  blown  into  the  sea,  whence  they  are 
drifted  to  new  places  of  growth.  The  species  is,  again  like  Siuiana 
bodily  aquavectent  in  dispersional  characters.  It  is  very  seldom,  if 
ever,  found  on  the  shores  of  bays  or  on  shores  guarded  by  partly  dry 
reefs. 

8.  Conocarpus  erectus  Linn.     Sp.  PI.  147. 

A  few  clumps  of  this  shrub  have  established  themselves  amongst 
the  Suriana  bushes  at  the  south  end  of  the  fringe  on  Perez  Island,  where 
the  shore  being  free  on  the  weather  edge  of  the  reef,  there  has  accumulated 
quite  a  congregation  of  wave  carried  species. 

Two  of  the  largest  trunks  of  this  species  showed,  by  the  armual 
rings,  a  growth  of  19  years. 

*As  Utowana  Cay  was  not  explored  this  statement  is  open  to  doubt. 


April,  1916.  Alack  an  Reef  —  Millspaugh  429 

From  its  association  on  these  cays  I  judge  that  the  fruits  are  aquavec- 
tent.     Its  growth  in  no  wise  gives  the  appearance  of  bird  transportation. 

9.  Flaveria  linearis  Lag.  Gen.  et  Sp.  Nov.  S3- 

A  few  plants  of  this  species  were  found  near  the  coral  cairn  on  Perez 
Island.  A  few  more  were  found  scattered  in  the  Sesuviimi  carpet  a  short 
distance  northwestward  from  the  cairn.  The  species  is  fairly  common 
on  the  coast  of  the  mainland  of  Yucatan  and  on  the  island  of  Cozimiel. 

This  dispersion  of  this  species  to  the  Alacran  Reef  must  have  been 
intestinally  avevectent  as  the  seeds  have  no  coma  and  the  position  of 
the  plants  on  Perez  savors  highly  of  resting  birds. 

10.  Portulaca  oleracea  Linn.  Sp.  PI.  445. 

A  few  individuals  of  this  species  were  found  scattered  amongst 
the  Sesuvium  of  Perez  and  Pajaros  cays.  It  had  not  yet  become  im- 
planted on  the  other  cays  visited. 

In  my  studies  of  the  intimate  dispersion  of  species  upon  sand  islets* 
I  have  fovmd  this  species  only  upon  inhabited  islands  and  then  generally 
in  areas  that  were  at  the  time,  or  had  been,  more  or  less  cultivated  for 
some  purpose.  The  position  of  the  plants  on  Perez  and  Pajaros  in 
no  way  indicate  homovectence,  though  on  Perez  this  might  have  been 
possible.  The  dispersional  indications  in  regard  to  this  species  are  not 
sufficiently  plain  to  me  at  this  time  to  permit  a  distinct  statement. 

11.  Cyperus  brunneus  Sw.  Fl.  Ind.  Occ.  1:116. 

One  clump  only  of  this  species  was  found  on  the  cays  that  on  the 
southwest  end  of  Perez  Island  just  beyond  the  Sporobolus  colony. 

This  species  is  quite  a  common  element  of  the  Antillean  strand  flora 
from  the  Bahamian  Archipelago  through  to  Vera  Cruz,  Mexico.  It 
occurs  in  places  all  along  the  Yucatan  coast  and  on  the  strands  of  the 
island  of  Mugeres. 

The  seeds  are  avevectent  per  pedis  et  intestinis. 

12.  Atriplex  cristata  H.  &  B.  ex  Willd.  Sp.  PI.  4:959. 

A  group  of  a  few  individuals  of  this  species  was  found  in  the  Sporobol- 
us colony  on  the  south  end  of  Perez  and  qmte  a  large  cluster  in  the  same 
association  on  Chica.  On  Pajaros  a  small  group  was  found  in  associa- 
tion with  the  Sesuviimi.  The  species  has  also  been  returned  from  the 
Yucatan  main  coast  at  Progreso  and  Silam. 

I  judge  that  the  fruits  are  'avevectent,  being  transported  on  the 
webbed  feet  of  the  booby,  and  that  the  cliunp  in  the  Sesuvitmi  of  Pajaros 
came  originally  from  the  older  implantation  on  Chica. 

*"  Flora  of  the  Sand  Keys  of  Florida,"  Field  Museum  of  Natural  History,  Botany, 
Vol.  2,  no.  5. 


430    Field  Museum  of  Natural  History  —  Botany,  Vol.  II 

13.  Cenchrus  carolinianus  Walt. 

This  species*  was  found  only  at  one  spot,  that  on  the  south  shore  of 
Perez  Island  near  the  clumps  of  Conocarpus  at  the  edge  of  the  Sporo- 
bolus  colony  at  that  point.  The  species  has  also  been  returned  from 
Cozumel  Island  but  not  from  the  Yucatan  mainland. 

The  species  is  avevectent  through  the  spiny  burs  clinging  to  the 
webbed  feet  of  the  booby. 

14.  Cenchrus  insularis  Scribn.     Field  Mus.  Bot.  2:26. 

This  new  species  is  represented  by  a  few  plantst  on  Pajaros  Island 
only.  These  were  all  in  full  ripe  fruit.  That  this  is  the  full  representa- 
tion of  so  strongly  a  differentiated  species  is  open  to  doubt  and  will  so 


C.  insularis. 


C.  echinatus 


remain  until  opportunity  is  had  to  visit  Utowana  Cay,  where  it  would 
seem  more  than  probable  that  a  fuller  growth  may  be  found. 

The  characters  clearly  differentiate  this  species  from  C.  carolinianus 
as  fotmd  on  Perez  Island;  in  many  of  its  characters  it  is  much  nearer 
C.  echinatus  as  found  abundantly  on  cultivated  lands  near  Izamal, 
eighty  miles  inland  on  the  main,  and  on  the  rocky  plain  south  of  Pro- 
greso.  I  am  strongly  inclined  to  judge  the  latter  species  to  be  its  parent- 
age. The  fruiting  characters  of  the  two  species  are  here  illustrated 
in  conjunction.  The  species  differ  in  the  size  of  inflorescence;  number 
and  size  of  the  involucres;  character  of  the  basal  bristles  (barbellate  in 

*Reported  as  C.  tribuloides  L.  in  Field  Mus.  Bot.  2 144. 

tThe  specimen  from  Cozumel  reported  as  this  species  under  the  description  of 
the  type  proves  to  be  C.  caroUnianus  Walt. 


April,  1916.  Alacran  Reef  —  Millspaugh  431 

C.  echinatus,  glabrous  in  C.  insiilaris);  and  in  the  shape  and  size  as 
well  as  the  nervation  of  the  first  glume. 

The  plant  is  dispersionally  avevectent,  the  burs  attaching  themselves 
by  their  sharp,  barbed  bristles  to  the  webbed  feet  of  swimming  birds 
during  their  walks  along  the  strand. 

15.  Philoxerus  vermicularis  (L.)  R.  Br.* 

This  species,  common  on  the  shores  of  the  lagoon  at  Progreso  and 
Silam  on  the  Yucatan  mainland,  is  found  on  the  Alacrans  only  on  a 
bare  spot  in  the  Sesuvium  colony  of  Perez  and  Allison  Islands. 

From  its  position  on  the  islands  I  am  strongly  inclined  to  judge  its 
dispersional  character  to  be  avevectent  through  the  agency  of  small 
migratory  birds. 

16.  Boerhaavia  repens  Linn.  Sp.  PI.  3.! 

This  species  was  found  only  on  one  of  the  bare  spots  in  the  Sesuvium 
carpet  of  Perez  Island,  where  it  nearly  covered  the  small  area  in  which  it 
had  become  implanted.  It  occurs  also  on  the  borders  of  the  lagoon  at 
Progreso  on  the  main  but  has  not  been  gathered  at  any  other  part  of 
the  Yucatan  region. 

In  regard  to  the  Alacran  Reef  the  dispersional  character  of  this 
species  is  avevectent,  the  viscous-glandular  fruits  attach  themselves  to 
the  feet  and  feathers  of  migratory  birds. 

17.  Opuntia  Tuna  (L.)  Mill.  Diet.  ed.  VIII  :3. 

Two  low,  spreading  cltimps  of  this  cactus  were  observed  growing  from 
the  interstices  in  the  cairn  of  old  coral  heads  thrown  up  in  the  center  of 
the  north  half  of  Perez  Island.  The  plants  were  vigorous  and  had 
apparently  well  adapted  themselves  to  their  environment. 

Their  location  plainly  indicates  that,  in  this  instance,  the  dispersional 
character  continues  to  be  avevectent.  That  some  migratory  bird, 
resting  from  flight  upon  the  cairn,  deposited  the  seed  between  the 
topmost  coral  heads  is  evident. 

18.  Scaevola  Lobelia  Murr.  Linn.  Syst.  ed.  XIII :i 78. 

One  individual  only  of  this  seaside  species  was  seen  upon  the  islets 
of  the  reef.  This  was  growing  directly  under  the  left  arm  of  the  little 
wooden  cross  erected  at  the  head  of  the  grave  on  the  north  end  of  Perez 
Island.  I  removed  a  portion  of  this  plant  for  herbarium  purposes: 
this  may  possibly  affect  its  continuance. 

The  position  in  which  the  plant  grew  leaves  no  doubt  as  to  the 
avevectent  character  of  its  dispersion. 

*Lithophila  vermiculata  Uline  in  Field.  Mus.  Bot.  2:39. 

tDr.  Heimerl  considers  our  Alacran  plant  to  be  nothing  but  a  form  transitional 
between  the  B.  viscosum  and  B.  hirsuta  of  Lagasca. 


